Resistance Welder Controller Using Current-Usage Feedback
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Solution Overview
Problem
In spot-welding of high tensile steel plates, existing resistance welder controllers that only consider usage rate fail to manage the electrical capacity effectively, leading to excessive usage of inverter transformers and reduced lifespan.
Innovation Solution
A resistance welder controller that monitors and controls welding current and usage rate, using a temperature detection unit and calculation units to ensure operations stay within the rated capacity, employing a usage rate measurement mode and average usage rate measurement mode to prevent transformer overheating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the resistance welder operates considering only usage rate, then the welding productivity is maintained, but the inverter transformer is used in excess of rated capacity and its life is adversely affected
Solution Approach 1:
The control unit continuously monitors welding current values and usage rates, and provides feedback control by comparing the product of welding current and usage rate against a predetermined threshold. This feedback mechanism prevents the inverter transformer from operating in excess of its rated capacity while maintaining welding productivity, thereby resolving the contradiction between productivity and transformer life.
Solution Approach 2:
The system changes the operational parameters by considering not only usage rate but also the product of welding current and usage rate. By dynamically adjusting the control parameters based on the relationship between welding current magnitude and usage rate, the system ensures the inverter transformer operates within safe limits while maintaining production efficiency.
2Manufacturing precision
If the welding current is increased for high tensile steel plates, then the welding quality is improved, but the inverter transformer is used in excess of rated capacity
Solution Approach 1:
The control unit monitors welding current values and calculates the product of welding current and usage rate in real-time. When this product approaches the predetermined threshold corresponding to the inverter transformer's rated capacity, the system provides feedback control to prevent excessive current usage, thereby maintaining welding quality for high tensile steel plates without exceeding transformer capacity.
Solution Approach 2:
The system dynamically adjusts the operational control based on the actual welding current values and usage rates. By making the control parameter (product of welding current and usage rate) dynamic rather than fixed, the system can accommodate varying welding requirements for different steel plate types while ensuring the inverter transformer operates within its rated capacity.
Data Source
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AI summary
To control operations of a resistance welder in consideration of a welding current and a usage rate. To include a control unit 120 that controls a welding current flowing through an inverter transformer 160, a current detection unit 125 that detects the welding current flowing through the inverter transformer 160, a usage rate calculation unit 130 that measures an energizing time and a point time interval of the welding current that has been detected, and calculates the usage rate of the inverter transformer 160 using the energizing time and the point time interval that have been measured, a storage unit 135 that stores an equivalent current curve indicating a relationship between a current value of the welding current and the usage rate of the inverter transformer 160 when the inverter transformer 160 is operated at a rated capacity, and a determination unit 140 that determines whether a relationship between the current value of the detected welding current and the calculated usage rate of the inverter transformer 160 exceeds the rated capacity of the inverter transformer 160 based on the equivalent current curve, continues an operation of the control unit 120 when the relationship between the current value of the detected welding current and the calculated usage rate of the inverter transformer 160 does not exceed the rated capacity of the inverter transformer 160, and stops the operation of the control unit 120 when the relationship between the current value of the detected welding current and the calculated usage rate of the inverter transformer 160 exceeds the rated capacity of the inverter transformer 160.